Sensor probe systems employing a housing and a sensor probe are commonly used by connecting them to a sensor well for sensing a predetermined parameter, e.g. temperature, pressure, vibration, heat. For example, when the parameter is heat or temperature, the housing and temperature sensor probe are connected to a heat transfer well or thermal well. The sensor probe is typically a hollow tube with one or more temperature sensors at the closed end and wires coming out the open end to connect to signal processing electronics. If multiple sensors are used in a probe they can be grouped for averaging their readings or spaced to obtain temperature gradients, for example. The sensor probe is disposed in the thermal well with the closed distal end of the sensor probe contacting the distal end of the well. The well physically protects the sensor probe and temperature sensors and provides good thermal transfer from the medium whose temperature is to be measured by the sensor probe. Good thermal contact between the distal ends of the well and sensor probe is important for accurate sensing. To ensure good contact, the distal end, or tip, of the sensor probe is pressed against the bottom, or distal end, of the well by a spring or other mechanical force. However, the wells vary in length depending upon the insertion depth required by the particular application. It is therefore necessary to have sensor probes of a number of different lengths: no one length of sensor probe can accommodate all applications and so a number of different sizes must be manufactured and inventoried.